Method of refrigeration and apparatus therefor



- Dec. 4, 1934. w. G. CLARK 1,982,789

METHOD OF REFRIGERATION AND APPARATUS THEREFOR Filed Feb. 8, 1932 3Sheets-Sheet l fn'uentor 1 ltorneyS 3 Sheets-Sheet 2 Inventor 1l/UI'IIQVA Dec. 4, 1934. w. G. CLARK METHOD OF REFRIGERATION ANDAPPARATUS THEREFOR Filed Feb. 8, 1932 METHOD OF REFRIGERAiION ANDAPPARATUS THEREFOR Filed Feb. 8, 1952 5 Sheets-Sheet 3 ZHIHHPatentecLDec. 4, 1934 METHOD OF REFRIGERATION AND APPARATUS THEREFOR'Walter Gordon Clark,

Los Angeles, Calif., as-

signor to Air Ice Research 8; Development Corp., Los DelawareApplication February 8,

25 Claims.

This invention relates to novel methods of utilizing gasifiablerefrigerants and to certain forms ofapparatus wherein the methods ofthis invention may be effectively carried out. 'The' in- 5 vention alsorelates to methods and apparatus in which various physical properties ofgasifiable refrigerants and of liquids are made available in theperformance of novel functions and results.

By' the term gasifiable refrigerants" as used 10 hereinafter, referenceis made to material such as liquefied or solidified carbon dioxide,sulfur dioxide, methyl chloride, etc. For purposes of lucidity, thesubsequent description of the methods and apparatus embraced by thisinvention will be particularly directed to methods and apparatus capableof being carried out or used.

- stand pressures of 900 pounds or more, with an additional satisfactorymargin of safety. A container of dimensions suflicient to receive blocks1 of solid carbon dioxide of commercial size, would under the abovestate of conditions, be exceedingly heavy. Furthermore, it is extremelydifficult to provide a gas-tight seal without resorting to threaded orbolted joints which are slow and ture either contemplated extremelyheavy and complicated devices, or did not fully utilize therefrigerating capacity of the materials.

This invention, on the other hand, provides means for storing anddispensing gasifiable refrigerants such as solid carbon dioxide, in asimple and effective manner. The pressure generated by vaporization orsublimation of a gasiflable refrigerant is utilized in sealing,strengthening and heat insulating the containers in which it is kept.The vaporization or sublimation of the refrigerants is controlled so asto maintain the Angeles, Calif., a corporation of 1932, Serial No.581,524

refrigerant at any desired and predetermined maximum pressure.Furthermore, the expansion of the gasifiable refrigerant is controlledfor the purpose of regulating the production of further quantities ofgasified refrigerant in quantities commensurate with theamount ofrefrigeration required.

In addition, the gasified refrigerant may be caused to perform usefulwork so that not only may a proper refrigerating temperature be main:tained in refrigeration chambers, but the refrigerant may be caused todisseminate, mix with and circulate within any enclosure which it isdesired to maintain at a relatively low temperature.

Moreover, the invention relates to a method of regulating the pressureof gasiflable refrigerants within a container by means of secondaryrefrigerants or freezable liquids. It concerns itself with novel methodsof heat insulating refrigerators, refrigeration chambers or othercompartments which it is desired to maintain at a low temperature; Themethods of this invention may be applied to the insulation of coldstorage receptacles, dispensing containers, refrigeration chambers,etc., and with the regulated supply of gasifled refrigerants toenclosures, rooms, box cars, and the like, for the purpose of keepingsuch enclosures cool.

arrangements ofyelements whereby the various objects and results towhich the methods of this invention are directed, may be attained. Itrelates, for example, to the production of means whereby gasifiablerefrigerants may be maintained at any predetermined maximum pressurewithin light weight dispensing containers; to the construction ofrefrigeration control units; to the construction of refrigerators; tothe provision of means whereby the expansion characteristics ofgasifiable refrigerants may be utilized to best advantage; to theprovision'of means whereby gasified refrigerants may exert a controlledrefrigerating effect and thereafter function to produce and maintainheat insulators, etc.

An object of this invention is to disclose and provide methods ofutilizing gasifiable refrigerants for the refrigeration of chambers,cold storage containers, enclosures, and the like.

Another object of this invention is to disclose and provide a method ofcirculating gasified refrigerants within enclosures which it is desiredto supply with a gasified refrigerant.

Another object of this invention is to disclose and provide a method ofstoring and dispensing gasified refrigerants.

An object of this invention is to disclose and provide a method ofstoring and dispensing refrigerants from limited containers in whichsaid The invention also concerns itself with novel refrigerants aremaintained at or below a predetermined maximum pressure.

A further object of this invention is to disclose and provide a methodof utilizing the heat absorbing capacity of vaporization of gasifiablerefrigerants for maintaining said refrigerants at a desired pressure andfor utilizing refrigerating capacity of said refrigerants mosteffectively.

'Another object is to disclose and provide a. method of utilizing theheat absorbing capacity of vaporization of gasiflable refrigerants forthe purpose of maintaining a secondary refrigerant in refrigeratingrelation to the gasiflable refrigerant, said secondary refrigerantacting as a structural material and at the same time acting as a heatinsulating material.

Furthermore, it is an object of this invention to disclose and provide amethod of insulating refrigeration chambers, cold storage receptacles,dispensing containers for gasiflable refrigerants, and similar objectsor bodies with a freez- 1 novel means for regulating the able liquid.

Moreover, it is an object of this invention to disclose and providemeans whereby the various objects enumerated hereinabove, as well asothers, may be readily attained. For example, it is an object of thisinvention to disclose and provide a novel and effective construction fordispensing containers for gasifiable refrigerants.

Another object of this invention is to disclose and provide a novel coldstorage or refrigerator construction.

A still further object is to disclose and provide gasiflablerefrigerants.

These and other objects, uses, advantages, functions and results of thisinvention will become apparent to those skilled in the art from thefollowing'description of the invention.

Although the invention may assume a great variety of forms and may beapplied to a plurality of different uses, the detailed description willbe limited to certain illustrative embodiments shown in the appendeddrawings, in which Fig. 1 is-a vertical section through one form ofdispensing container for gasiflable refrigerants.

Fig. 2 is an enlarged longitudinalsection through a form ofthermostatically controlled valve regulating means.

Fig. 3 is a front elevation, partly broken away, of a portion of arefrigerator embodying the invention. 1

Fig. 4 is a side elevation, partlybroken away, of the refrigeratorillustrated in Fig. 3. 4

Fig. 5 is a front elevation, partly broken away, of a refrigerationcontrol unit particularly adapted for use in cold storage houses, boxcars, etc.

Fig. 6 is a side elevation, partly broken away, of the refrigerationcontrol unit illustrated in Fig. 5.

As shown in Fig. 1, a suitable dispensing container for gasiflablerefrigerants may consist of a cylindrical container 1 provided with abottom 2. The container 1 may be provided with an inlet and in the caseof cylindrical containers, the openend of the cylinder may comprise theinlet. A suitable closure membergor cap is provided for the inlet to thecontainer. Preferably, the closure member is in the form of a capadapted to encircle a portion of the container adjoining the inlet. Asshown in Fig. 1, the cap 3 may be provided with a downwardly extendingflange 4. The cap preferably flts loosely over the inlet to thecontainer. A plurality of circum'ferentially vaporization of arranged.spacing pins or othersuitable spacing means such as protuberances 5, mayextend inwardly from the flange 4 so as to space the flange 4 from thecontainer 1. A plurality of outwardly extending circumferentially spacedpins or flange segments may extend from the upper edge of thecontainer 1. The purpose of these spacing means 5 will be evident fromthe subsequent description. The closure member 3 may be provided with anoutlet 6. Furthermore, the closure member may be provided with asuitable heating means such as, for example, an electrical resistancecoil 7 carried within a cavity within the closure member. Preferably,the resistance coil is carried both in the top and in the flange of theclosure member. A suitable terminal or plug 8 is carried by the closure3, facilitating the supply of electrical energy to the coil 7 wheneverit is desired to heat the coil. The container 1 is preferably positionedina case 10. The case 10 may well be made of light metal and'providedwith expansion joints r corrugations capable of permitting the case toexpand slightly. The container 1 is preferably spaced from the walls ofthe case 10, suitable spacing means being provided to insure'thisresult. Although any form of spacing means may be used, Fig. 1 indicatesbent metal spacers 11 for this purpose. Any suitable liquid is placed inthe space between the container 1 and the case 10, the liquid extendingup to about the top of container 1 and being permitted to enter thespace between the flange 4 of the closure and the container 1. I I

If a container of this general character is fllled with a gasiflablerefrigerant, such as solid carbon dioxide, and a closure placed over theinlet, (it being assumed for purposes of discussion that the closure isprovided with an aperture or outlet such as the outlet 6), and thefilled container then in' serted into, a case filled with water, thevaporization of the solid CO: within the container 1 will quickly causethe water to freeze. The ice thus formed substantially encloses thecontainer 1 and seals the closure 3 upon the inlet to the 'container 1.In this manner, the temperature within the container 1 is maintained atabout 32 F. and for this reason, the pressure within the con- .tainer isautomatically limited to approximately 500 pounds per square inch. Ithas been found that an ice seal of the character employed between thecontainer and the closure, has a strength of about 250 pounds per squareinch and therefore pressures which are much in excess of 500 pounds persquare inch, could be maintained within a container and the containersealed with ice, whenever ice is the seal between a closure member andthe container. Furthermore, it has been found that ice below 32 F; has athermal conductivity of only about 1.88 B. t. u.

per square foot per hour per 1 inch thickness per 1 F., and is thereforecomparable to cork insulation in effectiveness. Moreover the ice en'-circling and substantially enclosing the container 1 materiallyincreases the strength of the'container.

It is evident, therefore, that the container construction describedhe'reinabove employs a frozen liquid to perform a plurality of novelfunctions. The frozen liquid not only acts as a seal but insulates thecontainer and strengthens-it. Furthermore, the maximum pressure capableof being developed within the container is regulated by the freezingpoint of the liquid exteriorly of the container. Instead of.using'water, saturated or supersaturated solutions, brine, alcoholsolutions,

glycerine solutions, and other freezable liquids. or mixtures may beemployed. In this manner, the maximum pressure of a gasifiablerefrigerant within a limited container may be regulated by varying thefreezing point of a body of liquid substantially enclosing saidcontainer. .The heat absorbing capacity of vaporization or sublimationof the gasifiable refrigerant is therefore utilized in maintaining asecondary refrigerant in refrigerating relation to the gasifiablerefrigerant, and as long as suflicient heat absorbing capacity existswithin the container 1 to maintain the liquid frozen, a pressurecorresponding to the vapor pressure of the refrigerant at the freezingtemperature of the liquid surrounding the container, will be maintainedin the container.

As the maximum pressure capable of being generated within the containeris thus controlled, it is not necessary to employ heavy construction forthe container 1. When handling the solidified CO2 and using water ice asthe sealing means, it has been found that the container may be made ofsteel to A" in thickness. The exterior case 10 may be extremely light,being capable of only withstanding a pressure of 4 or 5 pounds persquare inch.

When the frozen liquid seal melts so that the cap is moved upwardly bythe action of the gas pressure within the container 1, the cap isprevented from being completely blown off by interengagement of theinwardly extending flange sections 5 and the outwardly extending flangesections or pins carried by the upper edge of the container 1. It is tobe understood that it'is necessary to partially rotate the cap upon thecontainer 1 before the cap may be removed.

Whenever it is desired to refill the container 1, a current may besupplied to the resistance coil 7 in the closure member, thereby meltingthe seal and permitting'the cap to be removed. Preferably, a pressurerelease valve is carried by the closure member 3 so that a pressure ofsay 500 pounds, is liberated before the closure is heated and unsealedfrom the container.

Although in the description given hereinabove reference" has been madeto a cylindrical container 1, it is to be understood that the containersmay be of any desired shape or size. Cylindrical forms are preferredbecause of their compactness, adaptability and high strength.

Dispensing units of the type illustrated in Fig. 1 may be utilizedwherever it is desired to store or dispense a gasifiable refrigerant.For example, they may be installed in refrigerated showcases, sodafountains and carbonated beverage dispensers, refrigerators, coldstorage rooms, and the like. When it is desired to dispense carbondioxide-from a container of this sort in regulated quantities so as tomaintain a desired low temperature in an enclosure such as arefrigerator, the container may be inserted into the refrigerator, theclosure member being then provided with a thermostatic valve 12positioned in a conduit leading to the container 1. For example, thevalve 12 may be connected to the outlet .6 formed in the ,closure member3.- The body portion of the valve f2 may be provided with a conical seat13 and a conical valve 14 adapted to cooperate with said seat. The valvemember 14 may be in the form of a rod made of a metal having negligiblecoeflicient of expansion. The upper end of the rod may be provided withan 'exteriorly threaded head 15 held in position within a tubular member16 attached to the body 12 of the valve. The tubular member 16 may bemade of brass or other metal end of a rear vertical partition 28 joiningthe or alloy, having appreciable coefficient of ex pansion. Means may beprovided for adjustably positioning the valve member 14 within thetubular member 16 as, for example, the groove 17, whereby the head 15and the rod 14 may be rotated within the tube 16, thus longitudinallymoving the-valve member 14. An outlet 18 may lead away from the valvebody 12.

By exposing. the thermostatic valve 12, and particularly the tubularportion 16 thereof, to the action of gases within the chamber which itis desired to refrigerate or cool, the volume of carbon dioxide or othergasifled refrigerant discharged from the container 1 through the outlet18 into expansion conduits, cooling coils, or the like, may beautomatically controlled. Variations in the temperature of the gaseswithin the chamber being refrigerated cause the member 16 to expand andcontract, thus changing the setting of the valve and regulating thepassage of gasified refrigerant therethrough.

Figs. 3 and 4 illustrate one form of refrigerator of high capacity,embodying forms of construction and methods embraced by this invention.A refrigerator of the type there shownis particularly adapted for use inhotels, homes, railroad dining cars, etc. It preferably comprises asuitable exterior housing 20 lined with insulating material 21. A thinmetallic but water-tight liner 22 is positioned within the case..Vertical partitions 23 and 24 are then positioned within therefrigerator, the partition 23 being spaced from the interior sheathing22 as by means of tie members 25 and 26. The tie members 25 and 26 maybe corrugated so as to permit expansion. The sheathing or liner 22 aswell as the partitions 23 and 24 may also be of corrugated metal.

A'horizontal member 27 may connect the lower ends of partitions 24 and23 as well as the lower rear portions of side partitions 23 and 24. Inveffect, therefore, partitions 23, 24 and 28 form an'enclosure connectedto the front of the refrig erator and supported above the inner liner22" by means of expansible supporting members 29.

The vertical side partitions 23 and 24 may be connected together bymeans of members 30 and 31, these members supporting suitable glazed orenameled refrigeration chambers 32 and 33. The open ends of theserefrigeration chambers 32 and 33 may be fastened to the front wall 34 ofthe refrigerator and be provided with suitable doors by means of whichaccess may be gained thereto. The refrigeration chamber 35 maybesupported above the bottom partition 27 by means of suitable supports36. r A suitable container for gasiflable refrigerants, such as thecontainer 1', may be positioned in the refrigerator, said containerbeing provided with a closure member 3 bearing a relief valve 40.Conduit means may communicate with the interior of the container 1 suchas, for example, the conduit 41, said conduit leading to athermostatic-ally controlled valve 42 exposed to the gases in one ofthe'refrigerating chambers of the re- 1 frigerator.

As shown in Figs. 3' and 4, the thermostat tube 16 of the thermostatvalve 42 extends 'into the refrigeration chamber 32; the gasifiedrefrigerant passing through the valve 42 passes through suitable coilssuround'i'ng the refrigeration chambers 33 and 35. The refrigerant,after passing through thermostat valve 42, may be discharged by conduit43 and pass through a series of co ls 44 around the lowermostrefrigeration chamber i 35 andthen through coils 45 around theintermediate refrigeration chamber 33. The partially-expandedrefrigerant may then pass by conduit 46 into the upper part of therefrigerator and be discharged into the insulation 21 therein. In actualoperation, the space within the resfrigerator, that is, the space withinthe inner lining or sheathing 22 and between said sheath- ,ing and theinterior partitions 23, 24, 28 and 27,

is filled with water or other suitable liquid. Such water preferablyextends upwardly to a height sufficient to substantially encircle andcover the container for gasifiable refrigerants 1'. The liquid level isindicated in Figs. 3 and 4 at 50. The gasifiable refrigerant vaporizesin thecontainer l' and is discharged through conduit 41. Thevaporization of the refrigerant causes the water or other liquidsurrounding the container 1', to freeze, thereby sealing the closuremember 3' and permittingthe generation of pressure within the container1'.

The thermostatic valve 42 responds to the temperature of the air withinthe refrigeration compartment 32 and permits the discharge of gasifledrefrigerant through the valve 42 and through conduit 43 into the coils44 and 45, thereby reducing the temperature in refrigeration chambers 35and 33 to a desirable low point. Inasmuch as the refrigerant is being.expanded in close proximity to the water-filled walls of therefrigerator, the water or other liquid therein freezes, forming a heatinsulating layer surrounding the refrigeration chambers 33 and 35. Thepartially expanded refrigerant is then discharged by conduit 46 into thelayer of insulating material 21 contained in the outer envelope of therefrigerator. Preferably, the heat insulating material 21 is porous andpermits the passage of carbon dioxide therethrough.

It has been found that layers of corrugated paper, loosely packedmineral wool, and similar materials form very effective insulation. In-

.sulating boards or panels made of corrugated paper are particularlyeffective. The carbon 4 dioxide sinks downwardly through the insulation,

displacing the moisture laden air generally existing in the pores of anyinsulating material, and

eventually the expanded carbon dioxide or other gasifiable refrigerantis discharged through suitable apertures 51 formed in the sub-floor ofthe refrigerator.

It will benoted that in a refrigerator of the .type shown in Figs. 3 and4, the refrigeration chambers are insulated by means of a freezableliquid. Furthermore, the freezable liquid assists in retaining andforming a container for the gasifiable refrigerant. The gasifiedrefrigerant controls its own rate of escape from the container 1' as thethermostatically controlled valve 42 responds to variations intemperature changes and such temperature changes are occasioned by theexpanding refrigerant. thermore, the vaporization or sublimation of therefrigerant in container 1 forms a body of ice or secondary refrigerantaround said container, the further expansion of the refrigerant in theexpansion conduits or coils reduces the temperature of the refrigerationchambers and freezes the insulating layers of ice, and the final stageof expansion of the refrigerant in the insulating lining 21 materiallyassists in maintaining the contents of the refrigerator at a uniformlylow temperature. Ordinary heat insulating materials contain mo'stureladen air, as has been stated hereinbefore, and moisture laden air hasFur a relatively high specific heat and is not an effective insulator.When solid carbon dioxide is the refrigerant used, the carbon dioxidegas is not only inherently at a low temperature when pass.ng through theinsulation 21, but in addi'- tion it is dry and therefore has arelatively low specific heat. It displaces the moisture laden airoriginally existing in the insulation.

The appreciable quantity of icesurrounding the refrigeration chambersand the container 1' not only acts as a heat insulator, but in additionfunctions as a cold storage so that in the event the supply of carbondioxide becomes depleted, a conditioned refrigerant is available fromthe ice.

It is to be understood that whenever reference has been made to ice,other freezable liquids are also contemplated. Furthermore, thearrangement of refrigeration chambers, coils and other details ofconstruction may be materially altered without departing from theinvention, the form of apparatus shown in the drawings being merelyillustrative of one type of device. Moreover, it is not necessary thatthe specific form of gasifiable refrigerant be employed in conjunctionwith refrigeration chambers which include wall spaces filled with afreezable liquid. A mechanical refrigeration unit could be substitutedfor the container for gasifiable refrigerants in a refrigerator of thetype shown in Figs..3 and 4 and merely the freezable liquid surroundingthe refrigeration chambers utilized.

Figs. 5 and 6 relate to a refrigeration control unit embodying theinvention, this refrigeration control unit being particularly adaptedfor use in cold storage houses, refrigerated box cars used 110 for theshipment of perishables, etc. As there shown, the refrigeration controlunit may comprise a heat insulated housing 55 which may advantageouslybe mounted on castors 56. Within said housing one or more expansiblecasings 57 115 may be positioned, said casings being preferably spacedfrom the interior walls of the housing 55. Within the casing 57containers 58 for the gasifiable refrigerant are positioned, the spacebetween the containers 58 and the casings 57 being 120 filled with afreezable liquid extending upwardly so as to contact with cappingmembers-59. Such capping members may be provided with a heating means.The housing 55 may also be provided with a motor means such as, forexample, the turbine wheel 60. A conduit 61.is provided for conveyingvaporized refrigerant from the container 58 to the turbine 60. Asuitable pressure regulating valve 62 is preferably positioned in theconduit 61. The valve 62 may be a thermostatic valve. The gasespartially expanded in the motor 60 are discharged into expansionconduits surrounding the containers 58 and casings 5'7.

For example, the gases expanded in the motor 60 may be discharged as bymeans 63 into the expansion conduits 64, 65 and 66. The expanded gasesmay then be discharged from the housing 55 through apertures or conduits67. These gases may be discharged directly into the room or refrigerator'car in which the unit is positioned, or they may be-discha'rged intooperative relation with a fan 68 adapted to mix the gases with air andcirculate the mixture within the enclosure to be cooled. The fan 68 mayadvantageously'be driven by the motor 60, thereby utilizing theexpansive force of the refrigerant not only in creating a reducedtemperature, but also furnishing power for circulating the refrigerantand mixing the same with air within the enclosure being cooled.

Means may be provided, such-as valved conduits 69 and 70,.foradmittingor discharging liquid from between the casings'7 and the container 58.Furthermore, valved gas conduit means 71 may be provided for liberatingpressure from within the containers 58 whenever it is desired to refillsaid containers with additional solidified or liquefied refrigerant.

Refrigeration control units of the type described hereinabove andillustrated in Figs. 5 and'fi, employ the heat absorbing capacity ofthe,

gasifiable refrigerants most efiectively. It is to be noted that theheat absorbing capacity of the refrigerants is utilized in .creating adesirable pressure within the containers 58 in forming a body ofsecondary refrigerant such as ice, which seals said containers andinsulates them against heat transfer, in generating power and incooling. an enclosure. Solidifled or liquefied carbon dioxide isparticularly adapted for use in devices of this type as, for example, inmaintaining controlled temperatures in passenger compartments of railwaycars or steamships, or in the refrigeration of ship compartments orrailway .cars containing perishables, as the carbon dioxide not onlyacts as a refrigerant, but in addition exerts a preservative effect.

Having thus fully described the invention and a number of itsmodifications, it is to be understood that the invention is not limitedto the specific embodiments described hereinabove but an enclosure to becooled.

instead includes all such changes, modifications, uses and adaptationsas come within the scope of the appended claims.

I claim:

1. A refrigeration control unit, comprising a heat insulated housingprovided with a container for gasifiable refrigerants, a body offreezable liquid substantially enclosing said container, 8. motor means,conduit means connecting said container with said motor means, apressure control valve in said conduit, gas expansion conduits in closeproximity to said body of freezable liquid,

means for conveying partially expanded gas from said motor means to saidexpansion conduits; a

fan operably connected to said motor means, means for directing gas fromsaid expansion conduits to said fan, said fan being adapted to mixexpanded gas from said motor means with air and circulate the mixturewithin an enclosure to be cooled.

2. A refrigeration control unit comprising a heat insulated housingprovided with a container for gasifiable refrigerants, a body offreezable liquid substantially enclosing said container, a

- motor means, conduit means connecting said container with said motormeans, gas expansion conduits in close proximity to said body offreezable liquid, means for conveying partially expanded gas from saidmotormeans to'said expansion conduits; a fan, and means for directinggas from said expansion conduits to said fan, saidfan being adapted tomix said expanded gas from said motor means with air and circulate themixture within 3. A refrigeration'control unit, comprising a containerfor gasifiable refrigerants, a body of freezable liquid substantiallyenclosing said container,.a motor means, conduit means connecting saidcontainer with said motor means, gas expansion conduits in close"proximity to said body of freezable liquid, means for conveyingpartially expanded gas from said motor means to said expansion conduits;and a fan, said fan being adapted to mix expanded gas from said motormeans motor means with air and circulate the mixture with air andcirculate the mixture within an enclosure to'be cooled.

,4. A refrigeration control unit, comprising a heat insulated housingprovidedwith a container for gasifiable refrigerants a body of freezableliquid substantially enclosing said container, a motor means, conduitmeans connecting said container with said motormeans, gas expansionconduits in close proximity to said body of freezable liquid, means forconveying partially expanded gas from said motor means to said expansionconduits, and gas discharge means from said expansion conduits.

5. A refrigeration control unit, comprising a storage container forgasifiable refrigerants, gas expansion conduits in heat exchangerelation to said container, conduit means connecting said container withsaid expansion conduits, a pressure control valve in said conduit meansadjacent said container, a motor means, conduit means connecting saidexpansion conduits with said motor means, and a fan operably connectedto said motor means, said fan being adapted to mix gas expanded in saidmotor means with air and circulate the mixture within an enclosure to becooled.

6. A refrigeration control unit, comprising a storage container forgasifiable refrigerants, gas expansion conduits in heat exchangerelation to said container, conduit means connecting said container withsaid expansion conduits, a motor means, conduit means connecting saidexpansion conduits with saidmotor means, and a fan, said fan beingadapted to mix gas expanded in said within an enclosure to be cooled.

'7. A refrigeration .control unit, comprising a heat insulated housingprovided with'a storage container for gasifiable refrigerants, gasexpansion conduits, a body of freezable liquid substantially enclosingsaid container and between said container and expansion conduits,conduit means connecting said container with said expansion conduits, amotor means; conduit means connecting said expansion conduits with saidmotor means, and a fan, said fan being adapted to mix gas expanded insaid motor means with air and circulate the mixture within an enclosureto be cooled.

8. A refrigeration control unit, comprising a heat insulated housingprovided with a storage container for gasifiable refrigerants, gasexpansion conduits, a body of freezable liquid substantially enclosingsaid container and between said container and expansion conduits,conduit means connecting said container-with said expansion conduits,and a pressure control valve in said conduit means adjacent saidcontainer.

9. A refrigeration control unit, comprising a. heat insulated housingprovided with a container for gasiflable refrigerants, gas expansionconduits in heat exchange relation to said container, conduit meansconnecting said container with said expansion conduits, a motor means,and conduit means connecting said expansion conduits with said motormeans.

10. A refrigeration control unit, comprising a storage container forgasifiable refrigerants, a bodyof freezable liquid substantiallyenclosing said container, gas expansion conduits in close proximity tosaid body of freezable liquid, conduit means connecting said containerwith said expansion conduits, a pressure control valve in said conduitmeans, and a gas discharge means from said expansion conduits.

11. A refrigeration control unit, comprising a heat insulated housingprovided with-a storage container forgasifiable refrigerants, a body offreezable liquid substantially enclosing said 'container, gas expansionconduits in close proximity to said body of freezable liquid, conduitmeans connecting said container with said expansion conduits, a pressurecontrol valve in said conduit means, and a gas discharge means from saidexpansion conduits.

12. A refrigeration control unit, comprising a storage container forgasifiable refrigerants, said container being provided with an inlet, acap member over said inlet, a body of freezable liquid substantiallyenclosing said container and in contact with said container and capmember, gas expansion conduits in close proximity to said body offreezable liquid, conduit means connecting said container with saidexpansion conduits, and gas discharge means from said expansionconduits.

13. A refrigeration unit, comprising a storage container for gasifiablerefrigerants, a body of freezable liquid substantially enclosing saidcontainer, gas expansion conduits, conduit means connecting saidcontainer with said expansion conduits, a pressure control valve in saidconduit means, and gas discharge means from said expansion conduits.

14. A refrigeration unit, comprising a container for gasifiablerefrigerants, a body of freezable liquid substantially enclosing saidcontainer, a motor means, conduitmeans connecting said container withsaid motor means, gas expansion conduits, and means for conveyingpartially expanded gas from said motor means to said expansion conduits.

15. A refrigeration unit, comprising a storage container for gasifiablerefrigerants, a body of freezable liquid substantially enclosing saidcontainer, gas expansion conduits, conduit means connecting saidcontainer with said expansion conduits, a thermostatically controlledvalve in said conduit means, and a discharge means from said expansionconduits.

16. In a refrigerator, the combination of a heat insulated housing, astorage container for gasifiable refrigerants, refrigerationcompartments in said housing, expansion conduits for a gasifiedrefrigerant in said housing and in heat absorbing relation to saidrefrigeration compartments and storage container, an admission conduitconnecting said expansion conduits with said storage container, a bodyof frozen liquid between said housing and refrigeration compartments,and a thermostatically controlled pressure valve in said admissionconduit, said thermostatically controlled valve being adapted toregulate the flow.

of gasified refrigerant from said storage container into said expansionconduits to keep said body of liquid frozen.

17. In a method of refrigeration, the steps of gasifying a gasiflablerefrigerant in a limited storage chamber, expanding said refrigerant toform a heat insulating body around said cham- .ber, passing thepartially expanded refrigerant through a motor, mixing the expandedrefriger ant with air, and circulating the mixture within an enclosureto be cooled.

-18. In a method of maintaining gasifiable refrige'rants below apredetermined maximum pressure, the steps of storing a gasifiablerefrigerant in a storage chamber sealed with a freezable medium, andregulating the maximum pressure within said chamber by varying thefreezing temperature of thesealing medium.

19. In' a method of refrigeration, the steps of gasifying a 'gasifiablerefrigerant in a limited chamber, partially expanding said refrigerantto freeze a liquid around said limited chamber, further expanding saidrefrigerant for refrigerating purposes in operative relation torefrigerating chambers, then passing the partially expanded refrigerantthrough a motor, mixing the expanded refrigerant with air, andcirculating the mixture within an enclosure to be cooled.

20. In a method of refrigeration, the steps of gasifying a gasifiablerefrigerant ina storage chamber provided with-a removable seal, andrestricting the escape of the gasified refrigerant from said chamber byfreezing a liquid between said seal and chamber.

21. In a method of refrigeration, the steps of gasifying a gasifiablerefrigerant in a storage chamber, expanding said refrigerant torefrigerate a chamber which it is desired to maintain at a lowtemperature, passing the partially expanded refrigerant through a motor,mixing the expanded refrigerant with air, and circulating the mixturewithin an enclosure other than said chamber to cool said enclosure.

22. A refrigeration control unit, comprising a storage container forgasifiable refrigerants, said container being provided with an inlet anda cap 195 member over said inlet, a body of freezable liquidin contactwith said container and cap member, gas expansion conduits, conduitmeans connecting said container with said conduits, a motor means,conduit means connecting said expansion conduits with said motor means,and a fan, said fan being adapted to mix gas expanded in said motormeans with air and circulate the mixture within an enclosure to becooled.

23. A refrigeration control unit, comprising a 15 housing containing astorage container for gasifiable refrigerants, said container beingprovided with an inlet and a cap member over said inlet,

a body of freezable liquid in contact with said container and capmember, gas expansion conduits, conduit means connecting said containerwith said expansion conduits, and a pressure control valve in saidconduit means adjacent said container.

24. A refrigeration control unit, comprising ahousing provided with acontainer for gasifiable refrigerants, said container beingprovided withan inlet and a cap member over said inlet, a body of freezable liquid incontact with said container and cap member, gas expansion conduitswithin said housing, conduit means connecting said container with saidexpansion conduits, a motor means, and conduit means connectingsaidexpansion conduits with said motor means.

25. A refrigeration control unit, comprising a 35 housing provided witha container for gasifiable refrigerants, said container being providedwith an inlet and a cap member over said inlet, a body of freezableliquid in contact with said container 'and cap member, a motor means,conduit means

